40 x 60' Metal Shop House Idea | Back Forty Building Co. Looking for a cost-effective way to have it all? Check out the Polson floor plan by Back Forty Building Co.! With 5 bedrooms, a garage/shop space, and over 3,000 sq. ft. of living space, this plan is perfect for steel build, hybrid, post frame, and stick build applications. Don't miss out on the opportunity to create your dream barndominium with the Polson plan!